Ultrashort wave resonance system



P 1938. H. E. HOLLMANN ULTRASHORT WAVE RESONANCE SYSTEM Filed Sept. 28, 1935 sou F05 r M M. 4 m m :INVENTOR HANS ERICH HOLLMANN L A Wm WM we 3 T0 All 00E OUTPUT' ATTORNEY- Patented Apr. 26, 1938 UNITED STATES 2,115,070 ULTRASHORT WAVE RESONANCE SYSTEM Hans Erich Hollmann, Berlin, Germany, assignor to Telefunken Gesellschaft fiir Drahtlose Telegraphic m. b. H., Berlin, Germany, a corporaticn of Germany Application September 28,1935, Serial No. 42,586 i In Germany September 15, 1934 '1 Claims. (01. 250-36) to 1000 megacycles by means of a back coupled tube transmitter, it is known to be very difiicult,

in matching the oscillatory circuit excited by the.

tube with the inner tube resistance (internal impedance of the tube) to maintain a sufficient operating voltage, and to provide an optimum of utilization of the tube, in view of the fact that the apparent resistance of the load circuit becomes steadily lower with increasing frequency due to the predominantly capacitive action of said load circuit. However, a much better matching and utilization of energy can be obtained by means of an oscillatory system in which the in- 20 ductance and the capacity are uniformly distributed.

The details of my invention will be better understood upon reading the following description in view of the accompanying drawing in which 25 Figure 1 shows diagrammatically one embodiment of an oscillatory system having symmetrical impedances in circuit with an electron discharge tube;

Fig. 2 shows a development of the underlying scheme, where four electron discharge tubes are symmetrically connected in circuit with a spherically formed load; and

Fig. 3 shows certain structural details of an embodiment of the invention in which two electron discharge tubes may be employed.

Referring to Fig. l, the resonance system which in fact represents the load of the tube, comprises two hemispherical cups, or bowls S1 and S2 mounted on a common axis in the form of a rod or tube A, A and representing the inductance, while the capacity is mainly formed by two equatorial flanges F1 and F2. The electrical condition of oscillation of such a hollow body corresponds to its mode of mechanical oscillation. In other words, the electrical oscillation is such that there will be an oscillation node in the center of the axis, whereas the potential loops (voltage antinodes) appear at the flanges, at which places, therefore, the grid and anode of the exciting oscillatory tube are connected in the manner shown in Fig. 1.

This known arrangement, however, has the defeet that the unilateral connections of the tubes disturb the uniform distribution of the capacity of the oscillatory circuit on the periphery of the flanges and cause a detrimental efiect by making it difficult to match the impedances of the os-' cillatory system. In order to avoid this defect, the present invention provides a more uniform excitation of the resonance system by replacing the single tube by several tubes distributed over the periphery of the resonance system. In View of this distribution of the individual tube capacities over the periphery of the spherical oscillatory circuit system and to the multiple excitation thereof from different points, there is obtained the fur ther considerable practical advantage that upper harmonics which tend to occur with great prominence in an unsymmetrical construction are, to a large extent, suppressed. If, on the other hand, it is desirable for special purposes such as for frequency multiplication, to provide a possibly large number of upper harmonics, the tubes may be irregularly distributed around the periphery so as to obtain oscillation loops (anti-nodes) at the centers of excitation established by the points of connection. While at fundamental oscillation all tubes operate in synchronism, they may in the'latter case also operate in push-pull, particularly if an oscillation node lies in the circuit between two tubes.

In some cases where the frequency to be generated is not too high and the power output required is not too great, i. e., the tubes employed are small enough, the tubes can be entirely accommodated within the hollow structure constituting the oscillatory system. A symmetric and radial arrangement of the tubes will probably be best suited for such a case because such an arrangement permits the cathodes to be directly connected to the center of the axis where an oscillation node exists, while the grid and plate leads can be directly connected to the two flanges. In this manner connections carrying high frequency do not appear at all outside the tubes, a

condition which is of particular advantage in connection with the proper phase adjustment of ultra-short wave feedback energy.

If the tubes are too large to be housed entirely within the oscillating hollow body, the glass of the tubes may protrude from openings provided in the resonance body without thereby causing an appreciable detrimental effect upon the electrical conditions of ultra-short wave transmitters. This idea of the invention is illustrated in the arrangement according to Fig. 3. The cathodes of the two tubes R1 and R2 shown in cross section are in the axis across which the heating current is' likewise introduced, while the remaining heating lines are brought out through the interior of the axial tube. The'direct grid'and plate potentials i are supplied across the two spherical cups; hence taken off'from the spherical'osc'illatory circuit structure either by means of a coupling loop, or across a supply line connectedtjo two, points in the axis and brought out through suitableaper r tures in the spherical cups. 7 t I claim:

an oscillatory circuit in theformoiapair of hem- 1' ispherical conductive members 'substantiallycon forming to a spherical surface and-having sub- 1 stantiallydistributed inductance and capacitance,

a plurality of space discharge tubes symmetrically disposed withrespect to said members, and means 7 V includingconnectionsbetween the input and out- 7 "onQsaid conductive members for balancing the put electrodes of said tubes and diiferent points impedances' of said oscillator internally and externally of said tubes. r

r ultra-short wave oscillator comprising an 7 oscillatory circuitrin 'theform of a pairof hemispherical conductivemembers substantially conforming to. a spherical surface and having substantially distributed inductance and capacitance,

' a plurality of space discharge tubes symmetrical- '13;- disposed with respect to said members and odes of said tubes-with heating current, said co-V disposed in recesses formed in said hemispherical members, and means including connections betweenthe input an d output electrodes of' said tubes and different points on said conductivev 9 membersfor balancing the impedances of said oscillatorginternally and externally of said tubes. 3. An: oscillator in accordance with claim 2 and having coaxial conductorsfor feeding the oathaxial conductors being disposed within the hemispherical surfaces of. said conductive members.

.,4.; Avery high frequency electron discharge ,de vice oscillator having, an electrically resonant oscillatory system constituted by a hollow conducting structure which is symmetrical aboutits axis,

1; An ultra-short wave oscillator comprising" V V characterized in that there are a plurality of oscillating electron discharge devices connect'ed to said'structure, the points of connection of said devices to said structure being spaced round the periphery thereof to provide additional capacities distributedaround said structure at said points of connection.

'5. A very high frequency thermionic valve oscillator having an electrically resonant oscillatory system constituted by a hollow structure with distributed inductance and capacity and consisting of an axially arranged conductordiametrically and symmetrically disposed with respect to a pair of substantially hemispherical conductive' caps arranged one at each end of said conductor,

cillatingelectron discharge devices with their .control grids connected to one can at or near, the

rim thereof and their anodes connected to the other cap at or near'the rim thereof, the points of,connection of the different devices to said caps i being spaced round the cap rims, the point of the anode of the same device to the other rim.

cillators each having an output circuit, and an electrically resonant oscillatory circuit effectively coupled in'parallel to the outputs of said oscillators, said oscillatory circuit comprising a hollow structure symmetrically disposed with respect and connected to an axially arranged conductor, said electron discharge devices being substantially" evenly distributed around said'hollow structure.

vice oscillator having an'electrically resonant oscillatory systemconstituted by a hollowconducting structure which'is symmetrical about its axis, f 40 7 HANS ERICl-I ,HOLLMANN.

connection of any control grid to onerim being" substantially opposite the point of connection of V '6. A short wave system comprising, in coinbination, a plurality of electron discharge device os- 7;; A very high frequency electron discharge de- 

